Preparation, quality characterization, service performance evaluation and its modification of sapphire crystal for optical window and dome application

Wang, Gui‐Gen; Zuo, Haibin; Zhang, Huayu; Wu, Qibao; Zhang, Mingfu; He, Xiaodong; Hu, Zhaohui; Zhu, Lin

doi:10.1016/j.matdes.2009.08.015

Cited by 50 publications

(12 citation statements)

References 23 publications

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“…Sapphire crystals are used mainly in optics and optoelectronics, where the anisotropy of properties is most in demand. For example, for high-strength optical glasses, it is preferable to use C(0001)-plane sapphire with zero birefringence [1]. Furthermore, the C-plane of sapphire has been used for a long time as a substrate for the formation of light-emitting devices [2][3][4].…”

Section: Introductionmentioning

confidence: 99%

Cathodoluminescent Analysis of Sapphire Surface Etching Processes in a Medium-Energy Electron Beam

Муслимов

Kanevsky

2022

Materials

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Sapphire crystals are widely used in optics and optoelectronics. In this regard, it is important to study the stability of crystals under external influence and the possibility of modifying their surfaces by external influence. This work presents the results of studying the processes of the action of an electron beam with an average energy of 70 keV or less under vacuum conditions on the surfaces of sapphire substrates of various orientations. The effect of etching a sapphire surface by an electron beam in vacuum at room temperature was discovered. The highest etching rate was observed for A-plane sapphire (the average pit etching rate was 10−6 µm3/s). It was shown that the rate of etching of a sapphire surface increased many times over when gold is deposited. An in situ method for studying the process of etching a sapphire surface using cathodoluminescence analysis was considered. Possible mechanisms of sapphire etching by a beam of bombarding electrons were considered. The results obtained could be important in solving the problem of the stability of sapphire windows used in various conditions, including outer space. In addition, the proposed method of metal-stimulated etching of a sapphire surface can be widely used in patterned sapphire substrate (PSS) technology and further forming low-dislocation light-emitting structures on them.

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Section: Introductionmentioning

confidence: 99%

Cathodoluminescent Analysis of Sapphire Surface Etching Processes in a Medium-Energy Electron Beam

Муслимов

Kanevsky

2022

Materials

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“…Progress in the preparation of large-sized sapphire (α-Al 2 O 3 single crystal) with high quality makes it an attractive infrared (IR)-transmission window candidate material. − However, in extreme military, metallurgy, and aerospace environments, sapphire windows may face further challenges such as harsh climates, flying sand, thermal shock, and high-power laser. Therefore, many issues should be considered for their practical application.…”

Section: Introductionmentioning

confidence: 99%

SiO₂/HfO₂ Laser Film with Enhanced Protection and Antireflection for Sapphire Infrared Windows at High Temperatures

Zhao

Wang

et al. 2021

ACS Appl. Electron. Mater.

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It is indispensable to achieve antireflection and protection of the sapphire (i.e., Al 2 O 3 single crystal) infrared window, especially in extreme environments such as high temperature and highenergy laser irradiation. Here, double-layered SiO 2 /HfO 2 films were deposited on sapphire by RF magnetron sputtering with subsequent annealing. The annealing of HfO 2 films in pure oxygen facilitates crystallization, as well as an obvious increase of the O/Hf ratio. The influences of the HfO 2 interlayer on the film microstructure, adhesive strength, film stress, laser-damage resistance, flexure strength, and infrared (IR) transmittance at various temperatures were investigated. The introduction of the HfO 2 interlayer leads to the densification of the SiO 2 protective layer, an improvement in adhesive strength, and an apparent reduction in film stress. A higher flexure strength at high temperature is observed for sapphire coated with a SiO 2 film, while the double-layer SiO 2 (670 nm)/HfO 2 (650 nm) film is superior to the single-layer SiO 2 film in terms of IR high-temperature transmittance and laser-damage resistance.

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“…Therefore, sapphire with the three different crystal orientations can be applied in different fields. For example, A-plane sapphire has been widely used in optical windows, microelectronics and high-temperature superconductors [7]. C-plane sapphire is often used as substrates of gallium nitride (GaN)-based light emitting diodes [8].…”

Section: Introductionmentioning

confidence: 99%

Focused Ion Beam Milling of Single-Crystal Sapphire with A-, C-, and M-Orientations

et al. 2020

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Sapphire substrates with different crystal orientations are widely used in optoelectronic applications. In this work, focused ion beam (FIB) milling of single-crystal sapphire with A-, C-, and M-orientations was performed. The material removal rate (MRR) and surface roughness (Sa) of sapphire with the three crystal orientations after FIB etching were derived. The experimental results show that: The MRR of A-plane sapphire is slightly higher than that of C-plane and M-plane sapphires; the Sa of A-plane sapphire after FIB treatment is the smallest among the three different crystal orientations. These results imply that A-plane sapphire allows easier material removal during FIB milling compared with C-plane and M-plane sapphires. Moreover, the surface quality of A-plane sapphire after FIB milling is better than that of C-plane and M-plane sapphires. The theoretical calculation results show that the removal energy of aluminum ions and oxygen ions per square nanometer on the outermost surface of A-plane sapphire is the smallest. This also implies that material is more easily removed from the surface of A-plane sapphire than the surface of C-plane and M-plane sapphires by FIB milling. In addition, it is also found that higher MRR leads to lower Sa and better surface quality of sapphire for FIB etching.

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Preparation, quality characterization, service performance evaluation and its modification of sapphire crystal for optical window and dome application

Cited by 50 publications

References 23 publications

Cathodoluminescent Analysis of Sapphire Surface Etching Processes in a Medium-Energy Electron Beam

Cathodoluminescent Analysis of Sapphire Surface Etching Processes in a Medium-Energy Electron Beam

SiO₂/HfO₂ Laser Film with Enhanced Protection and Antireflection for Sapphire Infrared Windows at High Temperatures

Focused Ion Beam Milling of Single-Crystal Sapphire with A-, C-, and M-Orientations

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Preparation, quality characterization, service performance evaluation and its modification of sapphire crystal for optical window and dome application

Cited by 50 publications

References 23 publications

Cathodoluminescent Analysis of Sapphire Surface Etching Processes in a Medium-Energy Electron Beam

Cathodoluminescent Analysis of Sapphire Surface Etching Processes in a Medium-Energy Electron Beam

SiO2/HfO2 Laser Film with Enhanced Protection and Antireflection for Sapphire Infrared Windows at High Temperatures

Focused Ion Beam Milling of Single-Crystal Sapphire with A-, C-, and M-Orientations

Contact Info

Product

Resources

About

SiO₂/HfO₂ Laser Film with Enhanced Protection and Antireflection for Sapphire Infrared Windows at High Temperatures